1. Field of the Invention
The present invention relates to a video signal processing device and a video signal processing method, and is suitably applied to a video signal processing device, for example, a newscaster who is reading aloud the news in the news studio is photographed and the video signal is generated and by inserting the other video signal into that video signal, the image of the other video signal is inserted into the prescribed frame in the background of the newscaster.
2. Description of the Related Art
Heretofore, in the news program production, by inserting the video image matching to the content of the news being read by the newscaster to the prescribed frame in the background of the newscaster, the images matching to the content of that news can be provided to the audience. Thus, the audience can comprehend the content of that news being read aloud by the newscaster more in detail according to the video image to be shown in the background of the newscaster.
Heretofore, these video signal insertion processings have been conducted according to the method to be discussed in the following.
Firstly, a source video signal to show the video image to be inserted to the prescribed frame in the background of the newscaster (heretofore referred to as a source video image) is formed (or reproduced from the VTR) and this is supplied to one end of an input terminal of a mixer through a video effector. At the same time, by photographing the newscaster in the studio, studio video signal is obtained and this is supplied to the other end of the input terminal of the mixer. This mixer combines the source video signal entered in one end of the input terminal and the studio video signal entered in the other end of the input terminal and supplies the resultant composite video signal to a monitor.
An operator supplies parameter for scaling up and down, moving and rotation to a video effector through an input device such as a trackball in order that the outer shape of the source video image fits to the prescribed frame in the background of the newscaster by observing the composite image displayed on the monitor. The video effector conducts the processing of scaling up and down, moving and rotation to the source video image based on the parameter supplied, and supplies the source video signal processed and the key signal showing the shape of the processed source video image to the mixer. The mixer inserts the source video signal into the position shown by this key signal from among studio video signal. The resultant composite video signal is supplied to the monitor as described above and displayed. The operator, repeating the parameter of scaling up and down, moving and rotation till the external shape of the source video image fits to the prescribed frame in the background of the newscaster by observing the composite image to be displayed, supplies to the video effector.
In the case of conventional device, by successively repeating these processings, source video image has been inserted to the prescribed frame in the background of the newscaster.
However, in the conventional insertion processing, the operator has to manually input the parameter necessary for the conversion processing, such as scaling up and down, moving and rotation of the source video image in utilizing the input device such as trackball until the shape of source video image fits to the prescribed frame in the background of the newscaster, and thus, it takes comparatively long time before the shape of source video image completely fits to the prescribed frame in the background of the newscaster and since the operator must conduct an input operation of the parameter during that period, it causes a problem that the operation becomes complicated.
As a method to solve this problem, there is a method disclosed in the U.S. Patent (U.S. Pat. Nos. 4,951,040 and 5,107,252). In this method, the operator inputs at least 4 points of corner position showing the shape after the source video image is converted by using the input means such as touch tablet and stylus. And the image conversion means converts said source video image in order that the corners of the source video image fit to 4 corners specified on the basis of the address signal showing 4 points of corner position entered. According to this method, the source video image can be inserted into the prescribed frame within a comparatively short period of time as compared with the method described earlier and the operator""s operation can be decreased.
However, according to this method in the case of inserting the source video image into the prescribed frame in the background of the newscaster, the operator must input corner positions by manually operating the input means such as touch tablet and stylus in order that each corner of the source video image fits to each corner of the prescribed frame in the background of the newscaster, and it is still insufficient on the point to simplify the operation of the operator.
In view of the foregoing, an object of the present invention is to provide a video signal processing device and a video signal processing method capable of further decreasing the operation task of the operator.
To obviate such problems according to the present invention, we provide a video signal processing device for inserting a source video signal into a predetermined area of a video signal to form a composite video signal, which comprises corner detection means for detecting the blue board area from a video signal formed by imaging an object with a blue board located in the background of the object, and detecting each corner position of the area, source corner specifying means for specifying each corner position of an image area within the source video signal to be inserted into the blue board area in the video signal, address generation means for calculating a transformation matrix for three-dimensionally transforming the image area into the blue board area based on the position information showing each corner position of the blue board detected by the corner detection means and the position information showing each corner position of the image area specified by the source corner specifying means, subsequently calculating an inverse matrix of the transformation matrix, and calculating address information for reading the source video signal from a memory in which the source video signal has been written, image conversion means for writing the source video signal in the memory and reading the source video signal written in the memory based on the address information generated by the address generation means to form a conversion source video signal which has the image area three-dimensionally converted and located at a position corresponding to the blue board area, and signal mixing means for mixing the conversion source video signal and the video signal to form a composite video signal which has the image area of the source video signal inserted into the blue board area in the video signal.
As described above, each corner position of the blue board area is detected from the video signal, and the transformation matrix for three-dimensionally converting the image of the image area so as to be located at a position corresponding to the blue board area is calculated based on the position information showing the detected corner positions and the position information showing each corner position of the image area of the source video signal to be inserted. The address information is generated based on the inverse matrix of the transformation matrix, and the source video signal is read from the memory based on the address information, thereby forming a transformed source video signal having the image area 3-D converted and located at the position corresponding to the blue board area. In this way, when a source video signal is inserted into the prescribed frame of a video signal, an image area to be inserted can be three-dimensionally converted and automatically inserted to the blue board area, which is the destination to which the picture area is inserted, without requiring the operator to input parameters indicative of a state after transformed as before, thereby making it possible to further decrease the operator""s operation.
The nature, principle and utility of the invention will become more apparent from the following detailed description when read in conjunction with the accompanying in which like parts are designated by like reference numerals or characters.